1. Field of the Invention
The present invention relates to weft thread magazine arrangements for warp knitting machines which have a pair of transport arrangements (one being provided to one side of the machine and the other to the other side of the machine); a carriage which continually carries weft threads from one transport arrangement to the other and back; a turning arrangement for the weft threads; and a roller delivery arrangement for delivering the weft threads to said turning arrangement, the delivery arrangement being driven in dependence upon the movement of the carriage.
2. Discussion of the Relevant Art
In a known weft thread magazine arrangement of this general type, (e.g., German OLS No. 28 12 032), the drive for the carriage is coupled with a roller delivery device for the provision of weft thread by means of a slip coupling. This slip coupling operates in such a way that during motion of the carriage in one direction, the circumference of the delivery roller moves at double the carriage speed and that during the movement of the carriage in the opposite direction the delivery rollers receive no drive at all. The temporary excess of delivered weft thread is taken up by a spring loaded storage device. In this way the exact amount of thread required for the back and forth motions of the weft thread is exactly metered. During the progress of the cycle however, the tension of the weft thread varies substantially.
It is further known (German OLS No. 24 53 682) that a plurality of weft threads may be delivered via a friction thread delivery arrangement. The circumferential speed of the friction rollers is at least twice as great as the maximum speed of the thread takeoff. The greater the tension of the particular weft threads the greater the forwarding speed through the friction rollers. This permits a reduction of tension differences and tension peaks.
Accordingly, there is a need to provide a weft thread magazine arrangement of the general type discussed hereinabove wherein, however, the variation of the tension values of the weft threads are reduced considerably below that which was heretofore possible.